Means for the removal and installation of



July 16, 1963 c B. KREKELER 3,097,547

MEANS FOR THE REMOVAL AND INSTALLATION OF CUTTER BITS IN MINING MACHINERY Filed May 5, 1959 INVENTOR. (Z4110! .5. /I//?'KEL ER,

BYMUJM ATTORNEYS.

United States Patent 3,0?7547 MEANS FOR THE REMOVAL AND INSTALLATION OF CUTTER BITS IN MINING MACHTNERY Claude B. Krekeler, Cincinnati, Ohio, assignor to The Cincinnati Mine Machinery (10., Cincinnati, Ohio, a

corporation of Ohio Filed May 5, 1959, Ser. No. 811,167 6 Claims. (Cl. 7680) This invention pertains to the field of mining machinery having socket members in which removable cutter bits are used. The socket members may be parts of cutter chains or parts of rotating heads. Perforations are provided in the socket members to receive the shanks of the cutter bits; and in recent years, in lieu of the set screws or other devices used to fasten the shanks of the cutter bits in the socket members, resilient holding means have been developed which permit the installation of a cutter bit by a simple driving operation, and its removal by a simple prying operation, both of which may be performed quite rapidly. This is a matter of great importance in the industry, since cutter bits must be changed very frequently, usually several times in a Working day, during which times the mining machine is necessarily out of service.

The present invention is not limited to any particular resilient holding means, but will be described in connection with the holding means of the copending application of the present inventor, Serial No. 728,476, filed April 14, 1958, now Patent No. 2,965,365, issued December 20, 1960, and entitled Bits and Holding Means Therefor, for the purpose of making an exemplary showing. To be fully satisfactory, the resilient holding means must strongly engage a prepared surface on the bit shank, and must be difficultly displaceable. Thus with a good resilient holding means a very considerable force must be exerted, not only in driving the bit home but also in prying the bit out of the socket member.

It should also be remembered that the changing of cutter bits must often be done under circumstances in which the operator is cramped for space, and finds it diflicult to assume a position in which he can exert maxi mum leverage with a prying bar. He may be so close to the work that any malfunction of tools can cause him serious injury. Yet again, he may find it necessary to do his work under inadequate light or even in total darkness.

As a consequence, ordinary tools are not generally adequate for the job. It is an object of the invention to provide a tool which is adapted for use under all of the disadvantageous conditions outlined above.

It is an object of the invention to provide a single tool useful both in the installation and in the removal of cutter bits.

It is an object of the invention to provide an installing means of such mass as to insure the striking of a blow of sufficient force to seat the cutter bit and to avoid the danger of an incompletely seated bit flying out of the socket member with possible injury to the operator. It is also an object of the invention to provide an installing means which will not injure the bit.

It is an object of the invention to provide a device for removing bits, which device, once engaged with the bit (in a manner which does not necessarily require visual observation on the part of the operator) will not come out of engagement with the bit accidentally whereby the operator may be injured. It is also an object of the invention to provide a device for removing bits which will exert very powerful upward force on the cutter bit through a short distance without taxing the strength of the operator and without requiring a great range of movement of the handle of the device.

3,097,547 Patented July 16, 1963 ice These and other objects of the invention which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications are accomplished by that construction and arrangement of parts of which the aforesaid exemplary embodiment will now be described. Reference is made to the accompanying drawings wherein:

FIG. 1 is a side elevational view of the tool of this invention.

FIG. 2 is a partial side elevation on an enlarged scale, the portion of the figure below the break line B being in section.

FIG. 3 is a partial face elevation of the tool.

FIG. 4 is a sectional view indicating the relationship of a socket member, a cutter bit and the tool of this invention at the start of a withdrawing operation.

FIG. 5 is a similar view showing the relationship of the elements at a later stage in the operation.

In order fully to explain the invention reference is made first to FIGS. 4 and 5, wherein 1 indicates a socket member having a perforation 2 to receive the shank of a cutter bit. The socket member, as indicated above, may be a part of a mining machine cutter chain link or a part of a driven head. An exemplary form of cutter bit is shown having a head 3 and a shank 4. At the juncture of the head and the shank there is a gauge limiting abutment 5 which serves to limit the depth to which the shank may enter the perforation in the socket member. The bit is indicated as having a hard cutting tip 6, usually formed as a separate piece of tungsten carbide, Carboloy or other suitable hard material, fastened to the body of the cutter bit as by Welding, brazing or the like. Cutter bits of the form illustrated are ordinarily made as steel forgings. They are provided with a shoulder 7, preferably slightly under cut as shown, and so located on the head that the shoulder 7 will be spaced from the top of the socket member 1 when the bit is in the fully engaged position as illustrated in FIG. 4.

While as stated above various forms of resilient retaining means may be employed, the form preferred cornprises a rigid steel rod 8 encased in a body of resilient, rubbery substance 9. A hole 10 is formed transversely in the socket memebr in such a way as partially to intersect the perforation 2. The resilient controlling means consisting of the rod 8 and the body 9 are located in this hole and extend from outer side to outer side of the socket member 1. The central portion of the body 9 of rubbery, resilient substance is cut away over the area of the perforation 2, so that the rod 8 projects at least partially into the perforation. If desired a groove 11 may be broached in connection with the hole 10, a corresponding ridge being formed on the body 9. This structure will prevent rotation of the resilient controlling means when installed in the socket member. The rod 8 may be shifted in position against the resistance of the rubbery resilient substance as will be clear from a comparison of FIG. 4 and FIG. 5; but the resistance to movement of the rod 8 is very great due to the inherent stifiness of the body 9.

The rear face of the shank 4 of the cutter bit is notched or otherwise treated so as to provide a surface 12 which will coact with the rod 8 of the resilient controller. It will be evident from FIG. 4 that when the rod 8 is in operating contact with the surface 12, the bit shank will be urged forwardly and downwardly in the perforation 2 of the socket member. In order to permit the installation of the bit by a driving operation, the lower rear corner of the shank is sloped or chamfered as illustrated at 13 so as to engage and depress the rod 8.

The resilient controlling device herein illustrated and briefly described is one form of the structures taught in the copending application referred to above. The resilient controlling means is itself readily replaceable in .arcuate COIltOIll.

the socket member as will be evident; and the resistance to movement of the rod 8 can be made any value desired by proper selection of the substance of the body 9. Natural or artificial rubbers may be used as well as the dhloroprenes such as neoprene; and the body 9, while it must remain distortable, is ordinarily made quite stiff.

In the structure as illustrated, the cutter bit is simply installed by placing the end of its shank in the perforation 2, after which the head of the cutter bit is struck a blow heavy enough to cause the sloping surface 13 to deflect the pin 8, and cause it to ride up the shank of the cutter biit until (when the cutter bit is fully home) the pin 8 engages the operating surface 12 on the cutter bit shank. 'Ilhe cutter bit may likewise be removed from the socket member by a prying action exerting a sufiicient force to cause the operating surface 12 to depress the pin 8 as illustrated in FIG. 5. The prying action is normally exented between the shoulder 7 and the top surface of the socket member 1. It will be evident that the force exerted in the prying operation will have to be large.

The invention contemplates the use of a tool such as is illustrated in FIGS. 1, 2 and 3. This tool comprises an elongated handle 14 having at one end a head 15. The lower end of the head beginning at about the line 16, is bifurcated and formed into two tines :17 and 18, which tines are spaced from each other a distance slightly more than the thickness of the head 3 of the cutter bits with which it is to be used.

The lower ends have rearward extensions 19 and 20, the lower edge surfaces of which are of circular or other It is intended that these elements shall have a camming action in relation to the top surface of the socket member 1, and hereinafter they will be referred to as cam elements.

At a point below the lower end of the handle 14 a pin 21 extends across between the cam elements 19 and 20.

The "pin may be fastened in place in any way desired.

In a simple and preferable construction it has a press or driving fit in perforations in the cam elements 19 and 20. The tool may be constructed as a metal forging, the

camming surfaces preferably being dressed by grinding or in some other suitable way; and the pin 21 is preferably made of hardened steel.

As illustrated in FIGS. 4 and 5, the tool may be brought 'to the workwith the handle lying at an angle of about 45 to the top surface of the socket member 1. The surfaces of the ca'm members 19 and 20 will be brought against the topsur'face of the socket member. The tool -may be slid along the top of the socket member until the head of the cutter bit 3 is embraced between the tines 17 and 18 and the cam members 19 and 20 as will be evident from the drawings. When the tool is in the position shown in FIG. 4 the pin 21 will lie closest to the top surface of the socket member and may easily be brought beneath the pry-out shoulder 7.

All of these operations are readily performed even in total darkness. If the handle of the tool is now swung in a counterclockwise direction as illustrated in FIG. 5, the pin 21 engaging beneath the shoulder 7 will forcibly lift the cutter bit by reason of the camming action of the members 19 and 20 on the top surface of the socket member 1. :It may be noted that this camming action will produce the greatest lifting force at the start of the operation of swinging the handle in the counterclockwise direction. This is of substantial value because the operating surfaces 12 on the cutter bits are frequently configured so that when the bit is driven fully home, the rod 8 of the resilient controlling means encounters a surface at a relatively high angle to the axis of the shank of the "cutter bit, increasing the security of the holding effect,

and causing the pin 8 to exert a powerful downward action on the shank. A very great force is required to cause such a high-angle surface to depress the pin 8. But when the pin has come out of contact with this particular surface, the gentler slope of other parts of the operating surface 12 are able to depress the pin more easily, until, when the pin 3 has passed beyond the operating surface 12 and onto the rear bit, a relatively much smaller force is required to withdraw the shank the rest of the way. It will be observed that the action of the camming members 19 and 2t), and the direction in which the handle of the tool is moved, serve to keep the tool in tight engagement with the cutter bit. Thus the location of bifurcations of the tool on both sides of the cutter bit, the undercutting of the shoulder 7, and the reactions of the tool against the bit and socket members as hereinabove described, coact to make it impossible for the tool to slip with respect to the cutter bit and injure the operator. The force required to be exerted by the operator is a very small fraction of the force exerted by the tool on the cutter bit, and the angularity through which the handle 14 of the tool need be swung to remove a bit is small, all of these factors making for easy operation in cramped quarters.

The head 15 together with its bifurcations as described contributes considerable mass to the operating end of the tool. This makes it readily possible to provide driving means in connection with the tool. An effective way of doing this is illustrated in FIGS. 1, 2 and 3. A hollow metallic cylinder or ring 22 is either formed integrally with the head 15 or is welded thereto as shown at 23. The head 15 closes one end of the ring. An impact means 24 in the shape of a cylinder is placed within the ring, where it may be held in any suitable fashion as for example by a pin 25. The impact means 24 may be of any suitable durable material but it is preferably made of a material which, unlike hard metal such as steel, 'will not tend to break the head of the cutter bit, or dislodge the cutting point 6 therefrom. A hard wood may be employed if desired, and so may rubbery substances having suflicient resilience to protect the bit head and sufficient hardness to transmit the force of the blow. A very excellent material for the purpose is a cylinder made from a strip of heavy rawhide Wound tightly upon itself and compressed. Thus, the tool of this invention may be moving them. It permits the installation and removal of cutter bits under cramped circumstances, and inasmuch as both operations may be carried on with no other guidance than that of touch, the light conditions under which the operator works are of substantially less importance. The tool is completely safe in use.

Modifications may be made in the invention without departing from the spirit of it. The invention having been described in a certain exemplary embodiment, what is claimed as new and desired to be secured by Letters Patent is:

l. A tool for removing cutter bits comprising a handle, substantially parallel spaced bifurcations at one end of thehandleadapted to lie on either side of a cutter bit, portions of said bifurcations extending in the direction of the axis of said handle, and other portions of said bifurcations extending at an angle to said axis, camming surfaces on the last mentioned portions of said bifurcations, and a pin extending across between said bifurcations and located substantially in line with the said handle axis so that when said camming surfaces are brought against the surface of another element such as the top of a socket member, the said pin will lie closest to said last mentioned surface when said tool handle is tilted with respect thereto, and so that said pin may be brought beneath an abutment means on said bit for removing it by a prying action, the said camming surfaces on said bifurcations acting, when said tool is swung upwardly to a higher angularity with respect to the surface of said socket member to cause said pin to exert a powerful lifting force on said abutment.

cated end of said tool, and a striking means mounted on the said solid portion of the said head.

3. The structure claimed in claim 1 wherein the said bifurcations are formed as part of a head at the said end of said handle, said head having a solid portion extending between the ends of said bifurcations and the said handle, the said head contributing substantial mass to the bifurcated end of said tool, and a striking means mounted on the said solid portion of the said head, and wherein said camming surfaces are formed at the ends of said bifurcations and extending substantially at right angles thereto in a direction away from the said pin.

4. The structure claimed in claim 3 wherein said striking means comprises a socket member attached to the solid portion of said head, and a striking element located within said socket means.

5. The structure claimed in claim 4 wherein said striking means is an element formed of a material softer than the material of said bit, whereby bit damage is avoided.

6. The structure claimed in claim 1 wherein end portions of said bifurcations are turned in the same plane as and at substantially right angles to the remainder of said bifurcations and said camming surfaces are formed on the end portions of said bifurcations.

References Cited in the file of this patent UNITED STATES PATENTS 786,174 Wood Mar. 28, 1905 892,228 Damon June 30, 1908 1,506,323 Heasley July 29, 1924 1,810,513 Zimmerman June 16, 1931 2,623,415 Dawson Dec. 30, 1952 2,655,399 McMillan Oct. 13, 1953 2,748,626 Daugherty June 5, 1956 FOREIGN PATENTS 572,229 Canada Mar. 17, 1959 

1. A TOOL FOR REMOVING CUTTER BITS COMPRISING A HANDLE, SUBSTANTIALLY PARALLEL SPACED BIFURCATIONS AT ONE END OF THE HANDLE ADAPTED TO LIE ON EITHER SIDE OF A CUTTER BIT, PORTIONS OF SAID BIFURCATIONS EXTENDING IN THE DIRECTION OF THE AXIS OF SAID HANDLE, AND OTHER PORTIONS OF SAID BIFURCATIONS EXTENDING AT AN ANGLE TO SAID AXIS, CAMMING SURFACES ON THE LAST MENTIONED PORTIONS OF SAID BIFURCATIONS, AND A PIN EXTENDING ACROSS BETWEEN SAID BIFURCATIONS AND LOCATED SUBSTANTIALLY IN LINE WITH THE SAID HANDLE AXIS SO THAT WHEN SAID CAMMING SURFACES ARE BROUGHT AGAINST THE SURFACE OF ANOTHER ELEMENT SUCH AS THE TOP OF A SOCKET MEMBER, THE SAID PIN WILL LIE CLOSEST TO SAID LAST MENTIONED SURFACE WHEN SAID TOOL HANDLE IS TILTED WITH RESPECT THERETO, AND SO THAT SAID PIN MAY BE BROUGHT BENEATH AN ABUTMENT MEANS ON SAID BIT FOR REMOVING IT BY A PRYING ACTION THE SAID CAMMING SURFACES ON SAID BIFURCATIONS ACTING, WHEN SAID TOOL IS SWUNG UPWARDLY TO A HIGHER ANGULARITY WITH RESPECT TO THE SURFACE OF SAID SOCKET MEMBER TO CAUSE SAID PIN TO EXERT A POWERFUL LIFITNG FORCE ON SAID ABUTMENT. 